Yes, try doing isometric holds at the top of the movement and how far are your reps from full ROM? If its a little then keep doing those reps and you should eventually be able to do full ROM. Front lever work would also increase lat strength.

Here is the thing... Most rowing/chinning movements are exercises where the last few inches are the hardest to complete. These types of movements are, in general, not given to training with the max effort style or with low reps. This is different than something like a bench press or a squat, where in general the hardest portion of the lift is in the middle, and it gets easier towards the end. Try rows or chins 2-3 times a week with the reps in the 5-10 range, and I bet you get better results.

Well, hot damn, I never considered this. I will keep working in higher rep ranges, then. Right now I'd been trying to do some max effort back work as my hamstring's hurt so it's limited my training options, but I guess it's back to the programming drawing board.